<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
</head>
<body>
<ul>
  <li>li1</li>
  <li>li2</li>
  <li>li3</li>
</ul>
<button>发布</button>
<script>
  var ul = document.querySelector('ul');
  var btn = document.querySelector('button');

  document.body.removeChild(btn);
  ul.removeChild(ul.children[0]);
</script>
</body>
</html>